I.C.20.i.1)

Sequelae external cause codes

Sequela are reported using the external cause code with the 7th character “S” for sequela. These codes should be used with any report of a late effect or sequela resulting from a previous injury. See Section I.B.10. Sequela (Late Effects)

ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026 (effective October 1, 2025). Published by CMS and NCHS. Reproduced for reference — always verify against the official CMS release.